Solar Coronal Modeling by Path-conservative HLLEM Riemann Solver

Abstract

In this paper, we employ a path-conservative HLLEM finite-volume method (FVM) to solve the solar wind magnetohydrodynamics (MHD) systems of extended generalized Lagrange multiplier (EGLM) formulation with Galilean invariance (G-EGLM MHD equations). The governing equations of single-fluid solar wind plasma MHD are advanced by using a one-step MUSCL-type time integration with the logarithmic spacetime reconstruction. The code is programmed in FORTRAN language with Message Passing Interface parallelization in spherical coordinates with a six-component grid system. Then, the large-scale solar coronal structures during Carrington rotations (CRs) 2048, 2069, 2097, and 2121 are simulated by inputting the line-of-sight magnetic field provided by the Global Oscillation Network Group (GONG). These four CRs belong to the declining, minimum, rising, and maximum phases of solar activity. Numerical results basically generate the observed characteristics of structured solar wind and thus show the code’s capability of simulating solar corona with complex magnetic topology.